1. How many wires can safety be installed in a junction box
Calculations or
How many wires can safety be installed in a junction box

2. 2 things happen when current flows in a conductor
HEAT

3. and a
MAGNETIC
Field

4. of electrical equipment
Heat is the arch enemy

5. Every conductor produces
HEAT
when current flows

6. so does the generated heat within the box
As the number of conductors in a junction box increases,
so does the generated heat within the box

7. Installing the maximum number of conductors in a junction box is limited by heat dissipation
                     

8. six inches of free conductor
The conductor length within the junction box is estimated at
six inches of free conductor

9. to the point of emergence from the cable sheathing
The six inches is measured from the termination point (splice or terminal screw)
to the point of emergence from the cable sheathing

10. Or from where the conductor exits a raceway

11. Each 14 gauge conductor installed in a junction box
requires 2.0 cubic inches of space
Regardless of how many
are in the box
The TOTAL is always ONE
Grounding conductor
Except the GROUNDING
conductor
ONE

12. The required space (2.0 cubic inches)
is determined by
                                            
the National Electrical Code Book

13. has a maximum current flow of
14 gauge wire
15 amps

14. generated safely within the
HEAT
allowable
internal heat
produces the maximum
15 amps of current
generated safely within the
Safe
Safe
14 gauge conductor

15. will slowly COOK the conductor
If more than 15 amps of current flows
the internal
heat
through a 14 gauge conductor
HEAT
will slowly COOK the conductor